scholarly journals Development and Implementation of an Anthropomorphic Underactuated Prosthesis with Adaptive Grip

Machines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 209
Author(s):  
Danilo Estay ◽  
Alvaro Basoalto ◽  
Jorge Ardila ◽  
Matías Cerda ◽  
Rodrigo Barraza
Keyword(s):  
Additive Manufacturing ◽  
Index Finger ◽  
Middle Finger ◽  
Distal Phalanx ◽  
Prosthetic Hand ◽  
Manufacturing Method ◽  
The Third ◽  
Flexion Extension ◽  
Sequence Of Movements ◽  
Little Finger

This paper describes the design of a prosthetic hand for wrist amputations. The mechanism considers the use of three actuators: one each for the movement of the little finger, annular finger, and middle finger. The second actuator controls the index finger, and the third controls the thumb. The prototype is considered relevant as it is able to move the distal phalanx in all fingers; the little, annular, and middle fingers are able to adapt to the shape of the object being gripped (adaptive grip). The sequence of movements achieved with the thumb emulate the opposition/reposition and flexion/extension movements, commanded by a single actuator. The proposed design was built by additive manufacturing and effortlessly achieves a large number of grips. Additionally, the prosthesis could perform specific movements, such as holding a needle, although this grip demands higher precision in the control of the fingers. Due to the manufacturing method, the prosthesis weighs only 200 g, increasing to 450 g when the actuators are included, therefore weighing less than an average adult’s hand.

scholarly journals Analysis of the effect of fingertip size for sex differences in current perception thresholds with transcutaneous electrical stimulation in healthy subjects

2021 ◽  
Author(s):  
Shin-ichiro Seno ◽  
Hideaki Shimazu ◽  
Eiki Kogure ◽  
Atsushi Watanabe ◽  
Hiroko Kobayashi
Keyword(s):  
Sex Differences ◽  
Healthy Subjects ◽  
Index Finger ◽  
Ring Finger ◽  
Middle Finger ◽  
Perception Threshold ◽  
Left Hand ◽  
Current Perception Threshold ◽  
Males And Females ◽  
Little Finger

Abstract Objective This study aimed to measure the current perception threshold (CPT) of five fingertips of the left hand in healthy subjects and analyze whether sex differences in perception thresholds are suppressed when adjusting for fingertip size among males and females. Results For fingertips from the thumb to the little finger, the males’ CPT values were 1.03, 0.83, 0.86, 0.86, and 0.88 mA; the females’ results were 0.63, 0.55, 0.54, 0.51, and 0.50 mA. The CPTs were higher in males than in females for every fingertip. Upon adjusting for fingertip length, the log-transformed CPT values were found to have sex differences, except for the index finger: thumb, t(20.05) = 3.493, p = 0.002; middle finger, U(30) = 44.50, p = 0.005; ring finger, t(30) = 55.50, p = 0.018; little finger, U(30) = 30.00, p = 0.001. Similarly, the CPT values, transformed into log values when adjusting for the fingertip area, were found to have sex differences for three fingertips: thumb, t(18) = 2.649, p = 0.016; middle finger, U(20) = 12.00, p = 0.004; ring finger, t(18) = 2.206, p = 0.041. According to this study, sex differences in CPTs were not completely abolished by adjusting for fingertip length or area.

Dimensions of the Metacarpo-Phalangeal Joint with Particular Reference to Joint Prostheses

1979 ◽  
Vol 8 (2) ◽  
pp. 75-80 ◽  
Author(s):  
A Unsworth ◽  
W J Alexander
Keyword(s):  
Index Finger ◽  
Middle Finger ◽  
Transverse Plane ◽  
The Other ◽  
Prosthesis Design ◽  
Single Centre ◽  
Articular Surfaces ◽  
Joint Prostheses ◽  
Centre Of Rotation ◽  
Little Finger

Sixty metacarpo-phalangeal joints were dissected and investigated to determine the shape, size and position of the articular surfaces with respect to the medullary canals of the metacarpal and the phalanx. The results show that the articular surfaces of the metacarpo-phalangeal joint have a single centre of rotation in the sagital plane and in the transverse plane. The joints of the little and ring fingers have radii of curvature in the sagital and transverse planes, which are almost equal (within 1.6 per cent) while those radii of the middle finger varied by 9 per cent. The index finger had a variation in radius from the sagital to the transverse plane of almost 13 per cent; the sagital plane radius being the greatest. This observation is the opposite of the other joints where the transverse radius is the greater one. The overall widths of the metacarpal heads were seen to vary from 13 mm in the little finger of females to 17 mm in the index finger of males (average). The medullary canals had axes which were not coincident with the centre of rotation of the joint but up to 3 mm displaced from it. These dimensional differences have important implications in prosthesis design.

Distribution of the Sensory Endings of the C7 Nerve Root and Its Clinic Significance

1994 ◽  
Vol 19 (1) ◽  
pp. 67-68 ◽  
Author(s):  
Y-D. GU
Keyword(s):  
Brachial Plexus ◽  
Nerve Root ◽  
Index Finger ◽  
Ring Finger ◽  
Middle Finger ◽  
Root Avulsion ◽  
Cutaneous Sensation ◽  
Little Finger ◽  
Sensory Endings

50 patients with root avulsion of the brachial plexus have been treated with contralateral C7 root neurotization. Abnormal cutaneous sensation was found on the index finger in 37 cases (74%), on the middle finger in 29 cases (58%), on the thumb in 19 cases (38%), on the ring finger in ten cases (20%), and on the little finger in one case (2%). Seven patients had no abnormal cutaneous sensation. It is suggested that the area of skin innervated by C7 is centred on the index finger together with the thumb and middle fingers.

Research on the Location and Segmentation Technologies in Palmprint Identification

2011 ◽  
Vol 474-476 ◽  
pp. 782-785
Author(s):  
Shuang Xu ◽  
Ji Dong Suo ◽  
Ji Yin Zhao
Keyword(s):  
Feature Extraction ◽  
Index Finger ◽  
Ring Finger ◽  
Region Of Interest ◽  
Middle Finger ◽  
Palmprint Identification ◽  
Roi Extraction ◽  
Image Position ◽  
Correct Image ◽  
Little Finger

In this paper, a method of palmprint segmentation and location is proposed. The proposed method focuses on region of interest (ROI) extraction of palmprint images which involve transition and rotation. Firstly, binary of palmprint image is used to define the edge of palmprint. Then we separate the fingers and palms and find the two valley points of the index finger and middle finger, ring finger and little finger. Finally, rotate image based on the two valley points and correct image position and create coordinate system according to valley points to determine ROI. This method provides a necessary preprocessing for further feature extraction and matching.The effectiveness of the proposed method is verified using the PolyU palmprint database.

scholarly journals A rare cause of osteomyelitis of distal phalanx: Candida lusitaniae

2021 ◽  
Vol 32 (2) ◽  
pp. 556-559
Author(s):  
Erdinc Acar ◽  
Ugur Bezirgan
Keyword(s):  
Candida Species ◽  
Specific Treatment ◽  
Middle Finger ◽  
Definitive Diagnosis ◽  
Distal Phalanx ◽  
Left Hand ◽  
The Third ◽  
First Case ◽  
Candida Lusitaniae

Osteomyelitis of the phalanx caused by Candida species are rare. A 49-year-old female patient was admitted to an external center with a splinter injury of the third phalanx of the middle finger of her left hand about 45 days ago. She was referred to our clinic with persistent pain and discharge, despite four-week antibiotherapy. Debridement and curettage were performed and partial excision of the distal phalanx at an appropriate level was done. Her complaints gradually resolved postoperatively with prescribed antibiotics for the pathogen identified as Candida lusitaniae based on the intraoperative cultures. At her three-month follow-up visit, treatment yielded near-excellent results. To the best of our knowledge, this is the first case of osteomyelitis of the distal phalanx caused by Candida lusitaniae in the literature, highlighting the importance of definitive diagnosis and pathogen-specific treatment, rather than empirical treatment, to achieve favorable results with cure.

scholarly journals Kinematic design of a finger abduction mechanism for an anthropomorphic robotic hand

2011 ◽  
Vol 2 (1) ◽  
pp. 33-40
Author(s):  
L.-A. A. Demers ◽  
C. Gosselin
Keyword(s):  
Index Finger ◽  
International Workshop ◽  
Robotic Hand ◽  
Kinematic Design ◽  
The Third ◽  
Little Finger

Abstract. This paper presents the kinematic design of an abduction mechanism for the fingers of an underactuated anthropomorphic robotic hand. This mechanism will enhance the range of feasible grasps of the underactuated hand without significantly increasing its complexity. The analysis of the link between the index finger and the third finger is first assessed, where the parameters are studied in order to follow the amplitude constraint and to minimize the coordination error. Then, the study of the mechanism joining the third finger and the little finger is summarized. Finally, a prototype of the finger's abduction system is presented. This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010), 19 August 2010, Montréal, Canada.

A review of additive manufacturing applications in ophthalmology

2021 ◽  
pp. 095441192110280
Author(s):  
Arivazhagan Pugalendhi ◽  
Rajesh Ranganathan
Keyword(s):  
Additive Manufacturing ◽  
Treatment Planning ◽  
Physical Object ◽  
Layer By Layer ◽  
Case Examples ◽  
Manufacturing Method ◽  
3D Cad ◽  
Stl File ◽  
Potential Applications ◽  
Manufacturing Applications

Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.

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